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Damaging din

LOUD noise outside schools seems to damage children's performance in exams. "The higher the noise levels, the lower the scores," says Bridget Shield of London South Bank University.

Her team measured noise levels during lesson times outside 142 primary schools in London. Then they compared the levels against published results of the standard national exams taken by all pupils at ages 7 and 11.

The noisier the environment, the worse the results, even when other possible causes of poor performance, such as social deprivation, were factored in. The researchers, who presented their results at a conference in Vancouver, Canada, this week, say that education authorities the world over should try to site schools away from loud traffic if possible, or to insulate or redesign existing buildings to shield pupils from noise.

Scared, but you don't knouu why

"THE lovely flowers MURDERER are in bloom again." In print, the threatening word is obvious. But if you saw that sentence on television and the word "murderer" appeared for a seemingly imperceptible time, you would still feel a twinge of fear, according to a study looking at how we register threatening words subconsciously.

Lionel Naccache of Salpétriére Hospital in Paris and colleagues showed three people threatening words, such as "rape", "knife", "kill", and "blood", interspersed with neutral words. The participants were already fitted with brain electrodes in preparation for surgery for epilepsy, so their brains' reactions could be recorded directly.

When the creepy words flashed up for just 29 milliseconds there was a strong response from the brain region involved in emotions and reaction to fear, the amygdala. Neutral words caused less than half the response. Participants were not aware of seeing the words. Consciously viewed words produced electrical activity that lasted about 300 milliseconds longer, which suggests that consciousness leads to additional brainwork (Proceedings of the National Academy of Sciences, vol 102, p 7713). "Word processing, not just for emotional words, but for all words, can occur in the absence of consciousness," Naccache told New Scientist.

Earliest lichen fossils found

FUNGI and algae first teamed up to form lichen 600 million years ago, according to newly discovered fossils from China. This makes them slightly older than the first fossils of complex soft-bodied animals, and far older than land plants.

Lichens are the product of a symbiotic relationship between algae, which produce food, and fungi, which provide moisture, nutrients and a protective framework. The new fossils come from south China, and were laid down in shallow sea water (Science, vol 308, p 1017).

Because lichens evolved many times, it is impossible to say whether the fossils are the ancestors of modern lichen, says team leader ShuhaiXiao of Virginia Polytechnic Institute and State University in Blacksburg.

The girl can't help it when a tasty male comes along

VORACIOUS female spiders just cannot help trying to eat suitors before sex. Why? If s their aggressive personalities.

Females of several spider and mantis species dine on their partners, but only after acquiring the sperm necessary to fertilise their eggs. By providing his mate with a good meal, the male increases his own reproductive success. But that doesn't explain the behaviour of females that opt for dinner instead of sex, as fishing spiders (Dolomedes triton) often do. "Eatingyourmate during or after copulating, thafs no big deal. Eatingyour mate beforehand, thafs weird," says Chadwick Johnson at the University of Toronto, Canada.

Even aggressive females do get to mate if their suitors escape theirfangs. But Johnson and Andrew Sih at the University of California, Davis, think the behaviour is part of a "voracity syndrome". They watched 60 female fishing spiders when males approached, and in encounters with predators and prey.

Femmeslatales who made the most attacks on males alsoshowed the mostfrenzied feeding, and were most da ring against predators. This, says Johnson, suggests these traits are linked, akin to human personalities (Behavioral Ecology and Sociobiology, DOI: 10.1007/s00265-005-09«-5).

Tempestuous young sun kept Earth in its place

Bibles dazzle with colour on the cheap

THE rich colours and ornate style of the 15th-century Gutenberg bibles, the first books to be printed with movable type, have led most art historians to assume they were created with some of the rarest, most expensive pigments of the time. Butthe pigments came from very common minerals, a new analysis of the books reveals.

Tracey Chaplin from University College London and her colleagues used a technique called Raman spectroscopy, which involves analysing the spectrum of reflected laser light, to examine the artwork in the bibles and the pigment debris that had fallen into the inner margins of the books over the centuries.

Although they identified 16 pigments, only six or seven were frequently used, including mercuric sulphide, or cinnabar, for bright reds, and malachite for olive greens (Analytical Chemistry, DOI: 10.1021/ac0503if6y). "The artists were conservative with their pigments and yet managed to create a wide array of colours by mixing them, or grinding into different particle sizes," says tea mm ember Gregory Smith. Most blues, for example, were derived from azurite, a common form of copper carbonate. "We had expected lazurite, an expensive mineral, to be the dominant blue pigment," says Smith. The findings could help preserve these valuable books.

MASSIVE and violent solar flares may have saved a nascent Earth from spiralling into the sun during the early stages of planet formation.

In the most commonly accepted model of planet formation, dust particles in the protoplanetary disc around a young star clump together to form rocks, which then stick together to form planetary cores. But the model fails to explain how the cores, once they reach a certain mass, can resist gravitational attraction and keep

A shocking way to grow bone

BLASTING bones with shock waves sounds like a bad idea, but it turns out that it stimulates bone growth. The non-invasive technique might help treat fractures that refuse to heal, and perhaps even reduce the need for hip replacements by encouraging ageing joints to regenerate.

Shock waves - single, high-pressure pulses - have long been used to break up kidney stones. They travel through soft tissue without causing damage but release their energy when they hit a hard substance such as bone. Doctors noticed decades ago that people who had multiple treatments for kidney stones grew extra bone on the pelvis, even though later studies showed the waves do not damage these bones.

Now Joerg Hausdorf's team at Ludwig Maximilians University in Munich, Germany, has studied the effect of shock waves on bone cells. The pulses stimulate production of an important bone growth factor, bFGH, Hausdorf told a meeting of the US and Canadian acoustical societies in Vancouver this week. He thinks shock waves activate the same growth mechanisms as stretching and pressure.

from falling towards the host star.

That's where solar flares come in, according to a team working on the Chandra Orion Ultradeep Project. The team studied 1400 embryonic stars in the Orion Nebula Cluster, using the Chandra orbiting X-ray observatory, and found 28 similar in size to the early sun, about 14 of which may have planet-forming discs around them. These stars are between a million and 10 million years old, and can provide clues as to how our4.6-billion-year-old sun may have behaved as an infant.

Roughly once a week, each of these stars lets loose a flare that reaches up to 10 times the star's radius. These enormous flares dwarf anything our sun can eject today in terms of energy, size and frequency.

Such gigantic solar flares could have helped counteract the inward migration of planetary cores by generating turbulence in the protoplanetary disc, and may have allowed Earth to survive its precarious youth. The work will appear in a future issue of the Astrophysical Journal Supplement.

Fish on the move as North Sea hots up

FISH in the North Sea are migrating to coolerwaters to escape warming seas.

Allison Perry and John Reynoldsof the University of East Anglia in Norwich, UK, and colleagues worked out the centres of abundance of 36 fish species based on data published over the past 25 years. During that time, the average temperature in the sea between the UK and Scandinavia has risen by 0.6 °C. They found that 21 species have moved: 15 to cooler latitudes and six to cooler depths (Science, DOI: 10.1126/science.HH322).

On average, centres of abundance have shifted by 173 kilometres. If warming trends continue unchanged, important commercial species such as blue whiting could vanish from the North Sea by 2050, the researchers say.

The impact on fisheries will depend on whether other commercial species move in from the south. "If you replace cod w ith red mullet thafsfine, but not if you replace cod with jellyfish," points out Hans Lassen, head of the scientific advisory programme at the International Council for the Exploration of the Sea, which monitors fish populations. At least 16 wa r mer-wate r s peci es a re now colonising the southern reaches of the North Sea, Lassen says. It is impossible to tell exactly what will happen as warming continues, Perry says. "There are so many complicated things going on that actual impacts are quite unpredictable."

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Comment and analysis

The great ecology challenge

Jacques Chirac, president ofthe French Republic, calls on us to reverse our collision course with biodiversity before the extinction rate reaches the point of no return

SINCE the Earth Summit in Rio in 1992, the environment has become a major concern for people across the world. Climate warming, the pollution of freshwater reserves, the destruction of habitats and the disappearance of many living species have made us realise that far from freeing humankind from nature, our extraordinary economic growth has given us an unprecedented responsibility towards it.

We can no longer ignore the evidence of environmental erosion: the destruction of primary tropical forests, home to over half of the planet's species; the shrinking of natural habitats due to demographic and urban growth; the slow demise of coral reefs, nearly one-third of which have already disappeared or suffered serious damage; the sharp decline in the numbers of large wild mammals.

The staggering pace of scientific and industrial progress over the past two centuries has placed us on a direct collision course with biodiversity, the product of millions of years of evolution. Species have always disappeared as a result of the natural renewal of ecosystems. Yet the current rate of extinction is estimated to be up to a thousand times higher than normal. Today, we know that nearly 16,000 known species are directly endangered, and some scientists fear that modern societies may be triggering the sixth great wave of extinction since life first appeared.

Our generation is probably the last with the power to stop this destruction before we reach a point of no return The international community has done a great deal of work since the Convention on Biological Diversity came into force in 1993. Yet it is fair to question how effective it has been, since biodiversity continues to recede. The goal set by the international conference in The Hague in 2002 of stopping the decline of global biodiversity by 2010 looks unattainable unless we act now.

We know enough to start taking action. Yet we do not yet have a gauge of all the potential consequences ofthe degradation of biodiversity. That is why I suggested at the international conference Biodiversity: Science and Governance, organised by France at UNESCO headquarters in January, that a global network of biodiversity experts be set up. I am pleased to see that the world's leading scientists have since backed my proposal.

The aim of the network would be to increase our knowledge of biodiversity and establish a scientific basis from which we can help the international community meet its responsibilities. This means mobilising all the scientific disciplines concerned, and calls for broad-based international cooperation, which could be achieved under the aegis of the UN Convention on Biological Diversity. This effort would focus on the need to reinforce global environmental governance, something France tirelessly campaigns for, in particular with its proposal to create a UN Environment Organisation, which

"Protecting biodiversity calls for radical changes in attitudes and lifestyles"

will be discussed by the world's heads of government at the UN summit in New York this September.

The global network of biodiversity experts should work on a number of points. The first is to extend the inventory of life on Earth. Barely 1.5 million species have been identified out of an estimated total of 5 to 30 million. This shows just how little knowledge we have. The second task is to understand the dynamics of ecosystems. Scientists are only just beginning to fathom the extreme complexity of relations between the different species and between species and their environment. This interdependence is the key to the fragile balance of each ecosystem and the entire biosphere. Humans cannot isolate themselves from it. This complexity, knowledge of which has been popularised by E. O. Wilson's remarkable work at Harvard University, is one reason why we have taken so long to become aware ofthe p roblem. The final task is to study the impact of climate change on biodiversity.

There is a precedent: the Intergovernmental Panel on Climate Change. This group's work since 1988 has brought about a scientific consensus on climate warming, which many initially refused to accept. An expert consensus such as this is just what political leaders need to justify action on biodiversity.

Protecting biodiversity, like combating climate change, calls for radical changes in attitudes and lifestyles. France is resolutely pursuing this objective with the inclusion of an environment charter in its constitution this year. This charter establishes biodiversity as a right and a collective heritage. It embraces the precautionary principle, which is vital when dealing with the deterioration of the living environment. To respond to the urgency of the situation, we have to step up the pace of action.

With our growing awareness that we are part ofthe biosphere and dependent on it as a whole, our civilisation has come to appreciate its fragility. Now is the time to embark on the path of responsible ecology, and to include in our quest for economic and human progress an awareness of our duties to nature and our responsibilities to future generations. We can do this if we all act together. •

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